docs: def keep_alive(self):
          '''
          Send a keep alive request periodically to make sure that the server
          is still alive. If not then try to reconnect.
          '''
          self.ssl_skt.settimeout(defaults.AUTH_KEEP_ALIVE_INTERVAL)
          while self.__up:
              try:
                  log.debug('Sending keep-alive message to the server')
                  self.ssl_skt.send(defaults.AUTH_KEEP_ALIVE)
              except socket.error:
                  log.error('Unable to send keep-alive message to the server.')
                  log.error('Re-init the SSL socket.')
                  self.reconnect()
                  log.debug('Trying to re-send the keep-alive message to the server.')
                  self.ssl_skt.send(defaults.AUTH_KEEP_ALIVE)
              msg = self.ssl_skt.recv(len(defaults.AUTH_KEEP_ALIVE_ACK))
              log.debug('Received %s from the keep-alive server', msg)
              if msg != defaults.AUTH_KEEP_ALIVE_ACK:
                  log.error('Received %s instead of %s form the auth keep-alive server',
                            msg, defaults.AUTH_KEEP_ALIVE_ACK)
                  log.error('Re-init the SSL socket.')
                  self.reconnect()
              time.sleep(defaults.AUTH_KEEP_ALIVE_INTERVAL)